The objectives of this research are to determine the effects of selected dietary states on the activity of the mixed function oxidases isolated from rat liver and lung which are responsible for the activation or inactivation of chemical carcinogens. Assessment of function will include measurements of (a) quantitative and qualitative changes in the metabolism of three model carcinogens, benzo(a)pyrene, 2-acetamidofluorene (2-AAF) and N-nitrosodimethylamine (DMN); (b) the influence of diet on the ability of the mixed function oxidases to alter the mutagenic potential of these carcinogens and; (c) in vitro binding of these carcinogen metabolites to native calf-thymus DNA and other nucleoproteins.